• Title, Summary, Keyword: design equations

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An Anthropometric Product Design Approach Using Design Structure Matrix (DSM): Application to Computer Workstation Design (Design Structure Matrix를 활용한 인체측정학적 제품설계 방법: 컴퓨터 워크스테이션 설계 적용)

  • Jung, Ki-Hyo;Kwon, O-Chae;You, Hee-Cheon
    • Journal of the Ergonomics Society of Korea
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    • v.26 no.3
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    • pp.111-115
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    • 2007
  • Design equations for anthropometric product design are developed by considering the geometrical relationships of design dimensions and anthropometric dimensions. The present study applied the design structure matrix (DSM) method to the development of design equations for a computer workstation, and compared design values from the design equations with corresponding design values of ergonomic recommendations and existing products. The relationships between design dimensions (e.g., legroom and worktable) were analyzed by a DSM, and then the application order of design equations (e.g., seatpan, backrest, armrest, legroom, and worktable in descending order) was determined. Next, design equations were developed by analyzing the geometric relationships between computer workstation design dimensions and anthropometric dimensions. Finally, design values for a computer workstation were determined by considering a standard posture defined and representative human models (5th, 50th, 95th %ile). The design values calculated using the design equations were similar with those of ergonomic recommendations found in literature and two commercial products measured in the study; however, some design values (e.g., seatpan height) were different due to discrepancy in standard posture. The DSM method would be utilized to systematically analyze the relationships between design dimensions for anthropometric product design.

Kinematic Design Sensitivity Analysis of Suspension System Using a Symbolic Computation Method (기호계산 기법을 이용한 현가장치의 기구학적 민감도 해석)

  • 송성재;탁태오
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.6
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    • pp.247-259
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    • 1996
  • Kinematic design sensitivity analysis for vehicle in suspension systems design is performed. Suspension systems are modeled using composite joins to reduce the number of the constraint equations. This allows a semi-analytical approach that is computerized symbolic manipulation before numerical computations and that may compensate for their drawbacks. All the constraint equations including design variables are derived in symbolic equations for sensitivity analysis. By directly differentiating the equations with respect to design variables, sensitivity equations are obtained. Since the proposed method only requires the hard point data, sensitivity analysis is possible in suspension design stage.

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Thermal Performance Evaluation of Design Parameters and Development of Load Prediction Equations of Office Buildings (사무소 건설의 설계변수 열성능 평가 및 부하예측방정식 개발)

  • 석호태;김광우
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.9
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    • pp.914-921
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    • 2001
  • The objective of this study is to evaluate the design parameters and to develop the cooling and heating load prediction equations of office buildings. The building load calculation simulation was carried out using the DOE-2.1E program. The results of the simulation was used as a data for ANOVA and multiple regression analysis which could develop the load prediction equations.

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Design Equation of a Coupled Beam to Limit Deflection of Modular Unit Structures (모듈러 유닛 구조물의 사용성 향상을 위해 연결된 보의 처짐 제한을 위한 설계식 개발)

  • Park, Ji-Hun;An, Seok-Hyun;Cho, Bong-Ho;Lee, Sang-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.471-475
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    • 2007
  • Design equations of coupling plates, which connects floor beam of the upper modular unit and overhead beam of the lower one in order to improve serviceability in vibration, are proposed. End conditions of the coupled beams is semi-rigid and the optimal location of the coupling plates are assumed. Rotational constraints for both ends of the coupling plate modeled with beam elements are released and flexibility method is applied to obtain deflection equations of the coupled beam. Proposed equations are defined using the flexibility of the coupling plate, of which size can be determined inversely. Based on numerical analysis, coefficients of the design equations are calibrated and the revised equations are verified to be useful in the design of the coupled beam.

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Optimization Design of Cascade with Rotor-Stator Interaction Effects (정익과 동익의 상호작용을 고려한 익렬의 공력 최적 설계)

  • Cho, J, K.;Jung, Y. R.;Park, W. G.
    • 유체기계공업학회:학술대회논문집
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    • pp.293-299
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    • 2001
  • Since the previous cut-and-try design algorithm require much cost and time, it has recently been concerned the automatic design technique using the CFD and optimum design algorithm. In this study, the Navier-Stokes equations is solved to consider the more detail viscous flow informations of cascade interaction and O-H multiblock grid system is generated to impose an accurate boundary condition. The cubic-spline interpolation is applied to handle a relative motion of a rotor to the stator. To validate present procedure, the time averaged aerodynamic loads are compared with experiment and good agreement obtained. Once the N-S equations have been solved, the computed aerodynamic loads may be used to computed the sensitivities of the aerodynamic objective function. The Modified Method of feasible Direction(MMFD) is usef to compute the

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Development of Live Load Moment Equations Using Orthotropic Plate Theory (직교 이방성 판 이론을 이용한 바닥판 활하중 모멘트 산정식 개발)

  • Ahn Ye-Jun;Nam Suk-Hyun;Park Jang-Ho;Shin Yung-Seok
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.749-756
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    • 2006
  • Because of the orthotropic elastic properties and significant two-way bending action, orthotropic plate theory may be suitable for describing the behavior of concrete filled grid bridge decks. Current AASHTO LRFD Bridge Design Specification(2004) has live load moment equations considering flexural rigidity ratio between longitudinal and transverse direction, but the Korea highway bridge design specification(2005) doesn't. The Korea highway bridge standard specification LRFD(1996) considers an orthotropic plate model with a single load to estimate live load moments in concrete filled grid bridge decks, which may not be conservative. This paper presents live load moment equations for truck and passenger car, based on orthotropic plate theory. The equations of truck model use multiple presence factor, impact factor, design truck and design tandem of the Korea highway bridge standard specification LRFD(1996). The estimated moments are verified through finite-element analyses.

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Kinematic Design Sensitivity Analysis of Suspension systems Using Direct differentiation (직접미분법을 이용한 현가장치의 기구학적 민감도해석)

  • 민현기;탁태오;이장무
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.1
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    • pp.38-48
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    • 1997
  • A method for performing kinematic design sensitivity analysis of vehicle suspension systems is presented. For modeling of vehicle suspensions, the multibody dynamic formulation is adopted, where suspensions are assumed as combination of rigid bodies and ideal frictionless joints. In a relative joint coordinate setting, kinematic constraint equations are obtained by imposing cut-joints that transform closed-loop shape suspension systems into open-loop systems. By directly differentiating the constraint equations with respect to kinematic design variables, such as length of bodies, notion axis, etc., sensitivity equations are derived. By solving the sensitivity equations, sensitivity of static design factors that can be used for design improvement, can be obtained. The validity and usefulness of the method are demonstrated through an example where kinematic sensitivity analysis of a MacPherson strut suspension of performed.

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Development of Load Prediction Equations of Office Buildings

  • Seok, Ho-Tae;Kim, Kwang-Woo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.10 no.2
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    • pp.65-71
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    • 2002
  • The objective of this study is to evaluate the design parameters and to develop the cooling and heating load prediction equations of office buildings. The building load calculation simulation was carried out using the DOE-2.1E program. The results of the simulation were used as data for multiple regression analysis which could develop the load prediction equations.

Limit load equations for partially restrained RC slabs

  • Olufemi, O.O.;Cheung, K.L.;Hossain, K.M.A.
    • Structural Engineering and Mechanics
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    • v.19 no.1
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    • pp.1-20
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    • 2005
  • The expertise required in the judicious use of nonlinear finite element (FE) packages for design-assistance purposes is not widely available to the average engineer, whose sole aim may be to obtain an estimate for a single design parameter, such as the limit load capacity of a structure. Such a parameter may be required for the design of a proposed reinforced concrete (RC) floor slab or bridge deck with a given set of geometrical and material details. This paper outlines a procedure for developing design-assistance equations for carrying out such predictions for partially restrained RC slabs under uniformly distributed loading condition, based on a database of FE results previously generated from a large number of 'numerical model' slabs. The developed equations have been used for predicting the peak loads of a number of experimental RC slabs having varying degrees of edge restraints; with results showing a reasonable degree of accuracy and low level of scatter. The simplicity of the equations makes them attractive and their successful use in the field of application reported in this paper suggest that the outlined procedure may also be extended to other classes of concrete structures.

Configuration sensitivity analysis of mechanical dynamics

  • Bae, Daesung
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.1
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    • pp.112-119
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    • 2001
  • Design sensitivity is an important is an important device in improving a mechanical system design. A continuum design consists of the shape and orientation design. This research develops the shape and orientation design sensitivity method. The configura-tion design variables of multibody systems define the shape and orientation changes. The equations of motion are directly differentiated to obtain the governing equations for the design sensitivity. The governing equation of the design sensitivity is formulated as an over determined differential algebraic equation and treated as ordinary differential equations on mani-folds. The material derivative of a domain functional is performed to obtain the sensitivity due to shape and orientation changes. The configuration design sensitivities of a fly-ball governor system and a spatial four bar mechanism are obtained using the proposed method and are validated against those obtained from the finite difference method.

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